1. Field of the Invention
The present invention relates to a display device, and more particularly, to a display device with an integrated touch screen.
2. Discussion of the Related Art
Touch screens are a type of input device that is included in display devices such as Liquid Crystal Displays (LCDs), Field Emission Displays (FEDs), Plasma Display Panel (PDPs), Electroluminescent Displays (ELDs), and Electrophoretic Display (EPDs), and allows a user to input information by directly touching a screen with a finger, a pen or the like while looking at the screen of the display device.
Particularly, the demand of display devices with the integrated in-cell type touch screen, which include a plurality of built-in elements for providing thin portable terminals such as smart phones and tablet Personal Computers (PCs), is recently increasing.
Display devices with an integrated touch screen are categorized into an optical type, a resistive type, a capacitive type, etc. according to a sensing type. Recently, the capacitive type is mainly used for increasing the sharpness of a screen and the accuracy of touch.
Technology of a display device with an integrated capacitive-type touch screen is discussed in U.S. Pat. No. 7,859,521, etc. Particularly, U.S. Pat. No. 7,859,521 is directed to a display device with an integrated mutual capacitance type touch screen.
In a related art display device with an integrated touch screen according to U.S. Pat. No. 7,859,521, a plurality of common electrodes for display are segmented into a plurality of touch driving areas and touch sensing areas, thereby allowing mutual capacitances to be generated between the touch driving area and the touch sensing area. Therefore, the related art display device measures the change in mutual capacitances that occurs in touch, and thus determines whether there is a touch input to the screen.
For this end, the common electrodes formed on the same layer are segmented into touch areas, each of which performs the function of a touch driving electrode and the function of a touch sensing electrode. In this way, since the common electrodes that perform the functions of the touch driving electrode and touch sensing electrode are formed on the same layer, these common electrodes (performing the same function) in a touch area are respectively connected to a plurality of driving electrode lines and sensing electrode lines, in an active area of a panel. Also, in order to prevent the contact between the common electrodes that perform the functions of the touch driving electrode and touch sensing electrode, the common electrodes that perform the function of one touch driving electrode are connected to each other through a contact hole and a driving electrode connection line, in the panel.
However, as described above, in the related art display device with the integrated touch screen, an aperture ratio decreases when the driving electrode lines, sensing electrode lines, and driving electrode connection lines are formed in the active area of the panel.
Further, in order for the related art display device with the integrated touch screen to simultaneously perform a display function and a touch function, common electrodes are respectively connected to a display driver Integrated Circuit (IC) and a touch IC. Also, the touch IC needs to perform a switching function that applies a common voltage to the common electrodes in a display driving of the panel, and applies signals necessary for touch sensing to the common electrodes in a touch driving of the panel.
Therefore, the related art display device with the integrated touch screen needs to separately include a Flexible Printed Circuit (FPC) for a touch IC and an FPC for a Display Driver IC (DDI) for connecting the common electrodes and the display driver IC, and a touch IC for switching the common voltage is required to be separately manufactured. Due to these limitations, a manufacturing process is complicated and increases manufacturing cost and time.
Moreover, in the related art display device with the integrated touch screen, the driving electrode lines that connect the touch IC and the common electrodes having the function of the touch driving electrode are respectively formed in a right inactive area and left inactive area of the panel. Thus, the Bezel width of the panel is enlarged undesirably.